Field of the Invention
The present invention relates generally to a floor box of the type commonly installed into the floor of a facility for providing temporary connections to utilities, and more particularly to an improved utility connection floor box which may be removed and replaced without requiring either the demolition and subsequent reconstruction of the floor in which the floor box is installed or the replacement or repair of the utility lines located in the floor and connected to the floor box.
Floor boxes are typically installed in locations at which connections to utilities such as electrical power, telephone, data, audio/visual, compressed air, water, and a drain will be required on a temporary or occasional basis. For example, convention and exhibition facilities require that connections to utilities be available at a large number of different locations throughout the facility, and that exhibitors be able to connect to utility connections located in the floor boxes. Since conventions or exhibitions are typically held for a matter of several days or a week, it will be appreciated that such connections are only used for short periods of time between setup and teardown of the displays or exhibitions.
However, convention or exhibition facilities in most large cities will be in more or less continuous use throughout the year, with a large number of different shows or exhibitions coming and going in rapid succession. It will also be appreciated that the use of floor boxes offers ready connections to utilities in a manner which is unobtrusive, and which does not require a great deal of time to set up or run electrical and plumbing lines. However, in order to afford the maximum degree of flexibility in configuring exhibit areas, it will be appreciated that a relatively large number of such floor boxes will be installed throughout the convention or exhibition facility.
Such floor boxes are installed at the time the facility is constructed, and are recessed into the concrete floors, which may be either slab on grade or structural floors. The floor boxes are typically made of either electro-galvanized steel, painted carbon steel, or stainless steel. The floor boxes are open on the top side thereof, and have a frame typically made of angle iron located at the top of the box. The floor boxes have covers which fit into the angle iron frame, with the covers typically being either steel plate or cast iron. More recently, cast aluminum has also been used as a material instead of steel plate or cast iron.
The installation of the typical floor box is made by first attaching the angle iron frame to the top of the floor box. The floor box is then set place and temporarily supported on concrete blocks or 2".times.4" blocks, with the angle iron frame being located at the level at which the floor surface will be when the slab or floor is poured. Holes are cut into the sides and bottom of the floor box for connections to utilities. The utility lines are then run and plumbed, and are permanently connected to the floor box through the holes which were cut therein in the conventional manner.
Re-bar for the slab or floor is then installed, and the concrete for the slab or floor is then poured. The cement in the concrete permanently "glues" the floor box into the slab or floor, and the utility lines extending into the floor box serve as dowels to make the installation of the floor box permanent. The concrete completely surrounds the floor box, and is level with the angle iron frame. When the cover is placed on the floor box, it is at the same level as the concrete slab or floor.
Thus, when the floor box is not being used, it serves as a part of the floor surface, and may be walked on or driven over. Since it is necessary for delivery trucks to drive onto the floor to deliver loads of materials for a convention or exhibit, the covers must be able to support heavy loads. The design criteria used for wheel loading is "highway" wheel loads, which are approximately 15,000 pounds over a 9 inch by 15 inch footprint. Some floor box covers are damaged or destroyed by the greater wheel loads imposed by forklifts, particularly hard-wheeled forklifts. Such loads can also damage a floor box to the point where it may require replacement.
One of the most serious problems encountered with floor boxes is corrosion. Since the floor boxes are typically made of steel, they can and do rust, particularly in northern climates where they are exposed to salt-laden water from melted snow picked up by the trucks on the highways. The water drips into the floor boxes, where the salt tends to greatly accelerate the rusting process. Such corrosion eventually results in the floor box deteriorating to a point at which it must be replaced.
Other problems which can result in the floor box needing to be replaced are fire, obsolescence, or physical damage caused by misuse. It will at once be appreciated by those skilled in the art that when the floor box is either unusable or when it has deteriorated to a certain point, it must be replaced. In addition, the facility may decide to upgrade their exhibitor services, but to do so means that the floor box would have to be replaced. In order to replace a floor box, the concrete slab or floor must be jackhammered to remove the box and to obtain access to the supply lines and plumbing. Frequently, the supply lines and plumbing are damaged in the process of removing the floor box, further exacerbating the replacement process. Replacement of a floor box is a difficult, time consuming, and expensive process, to say the least.
It is accordingly the primary objective of the present invention that it provide a floor box which may be relatively easily removed from the concrete slab or floor and the cover frame without requiring the slab or floor to be broken. It is a closely related objective of the removable floor box of the present invention that it may be reinstalled in the slab or floor and the cover frame without requiring any cement to be poured and with a similar degree of ease to that associated with its removal. It is a further primary objective of the present invention that the fittings connected to the removable floor box can be removed from the old floor box and reconnected to the new floor box easily and without necessitating the replacement of any of the lines or plumbing.
It is a further objective of the removable floor box of the present invention that it be provided with a cover which fits on the floor box in a water resistant manner, even though there are access doors which are located in the cover. It is a still further objective of the removable floor box of the present invention that the cover be designed so that it can support even large loads (such as a forklift with its maximum load, about to tip over so that most of its weight is on its front wheels) without damage to either the cover or the floor box. It is yet another objective of the removable floor box of the present invention that it may be made of a material which is completely resistant to corrosion.
The removable floor box of the present invention must be of a construction which is both durable and long lasting, and it should also require little or no maintenance to be provided by the user throughout its operating lifetime. In order to enhance the market appeal of the removable floor box of the present invention, it should also be of relatively inexpensive construction to thereby afford it the broadest possible market. Finally, it is also an objective that all of the aforesaid advantages and objectives of the removable floor box of the present invention be achieved without incurring any substantial relative disadvantage.